Maxon motor doesn't spin - BOOSTXL-DRV8301 and LAUNCHXL-F28027

Use lab02c and increase RES_EST_CURRENT until it starts and keeps spinning at the RampUp state.

Make sure the flux_est_freq is at (60.0) to (100.0) Hz

Hello,

Just so that I know what should the upper limit be? The motor spec has 5A as the current limit, driving 10A briefly didn't spin the motor.

Cheers,

Rich

this motor should start spinning up during motor ID with 2.0 A or less

are you using proj_lab02c?

you can upload or post your user.h if you wish

there must be another issue.

Hello,

Finally had time to play with the motor. I have swept USER_MOTOR_FLUX_EST_FREQ_Hz from 60 - 100Hz (no big difference), increased USER_MOTOR_RES_EST_CURRENT to 4A (the motor turned upto approx 3Hz, then stalled).

Here are the motor parameters:

#elif (USER_MOTOR == Maxon)
#define USER_MOTOR_TYPE MOTOR_Type_Pm
#define USER_MOTOR_NUM_POLE_PAIRS (7)
#define USER_MOTOR_Rr (NULL)
#define USER_MOTOR_Rs (0.307/2)
#define USER_MOTOR_Ls_d (0.188e-03)
#define USER_MOTOR_Ls_q (0.188e-03)
#define USER_MOTOR_RATED_FLUX (0.03)
#define USER_MOTOR_MAGNETIZING_CURRENT (NULL)
#define USER_MOTOR_RES_EST_CURRENT (4)
#define USER_MOTOR_IND_EST_CURRENT (-1)
#define USER_MOTOR_MAX_CURRENT (5)
#define USER_MOTOR_FLUX_EST_FREQ_Hz (75.0)

Hopefully you can see something obviously wrong (apart from FLUX which came from experimentation via GUI).

I doubt it's a hardware failure as I also have the DRV8301 HV kit and it's just the same there, though obviously with the 28069 processor based software.

The rest of the user.h file is here (except the other unused motor data):

// **************************************************************************
// the defines

//! \brief CURRENTS AND VOLTAGES
// **************************************************************************
//! \brief Defines the full scale frequency for IQ variable, Hz
//! \brief All frequencies are converted into (pu) based on the ratio to this value
//! \brief this value MUST be larger than the maximum speed that you are expecting from the motor
#define USER_IQ_FULL_SCALE_FREQ_Hz (800.0) //(800.0) // 800 Example with buffer for 8-pole 6 KRPM motor to be run to 10 KRPM with field weakening; Hz =(RPM * Poles) / 120

//! \brief Defines full scale value for the IQ30 variable of Voltage inside the system
//! \brief All voltages are converted into (pu) based on the ratio to this value
//! \brief WARNING: this value MUST meet the following condition: USER_IQ_FULL_SCALE_VOLTAGE_V > 0.5 * USER_MOTOR_MAX_CURRENT * USER_MOTOR_Ls_d * USER_VOLTAGE_FILTER_POLE_rps,
//! \brief WARNING: otherwise the value can saturate and roll-over, causing an inaccurate value
//! \brief WARNING: this value is OFTEN greater than the maximum measured ADC value, especially with high Bemf motors operating at higher than rated speeds
//! \brief WARNING: if you know the value of your Bemf constant, and you know you are operating at a multiple speed due to field weakening, be sure to set this value higher than the expected Bemf voltage
//! \brief It is recommended to start with a value ~3x greater than the USER_ADC_FULL_SCALE_VOLTAGE_V and increase to 4-5x if scenarios where a Bemf calculation may exceed these limits
//! \brief This value is also used to calculate the minimum flux value: USER_IQ_FULL_SCALE_VOLTAGE_V/USER_EST_FREQ_Hz/0.7
#define USER_IQ_FULL_SCALE_VOLTAGE_V (24.0) // 24.0 Example for boostxldrv8301_revB typical usage and the Anaheim motor

//! \brief Defines the maximum voltage at the input to the AD converter
//! \brief The value that will be represented by the maximum ADC input (3.3V) and conversion (0FFFh)
//! \brief Hardware dependent, this should be based on the voltage sensing and scaling to the ADC input
#define USER_ADC_FULL_SCALE_VOLTAGE_V (26.314) // 26.314 boostxldrv8301_revB voltage scaling

//! \brief Defines the voltage scale factor for the system
//! \brief Compile time calculation for scale factor (ratio) used throughout the system
#define USER_VOLTAGE_SF ((float_t)((USER_ADC_FULL_SCALE_VOLTAGE_V)/(USER_IQ_FULL_SCALE_VOLTAGE_V)))

//! \brief Defines the full scale current for the IQ variables, A
//! \brief All currents are converted into (pu) based on the ratio to this value
//! \brief WARNING: this value MUST be larger than the maximum current readings that you are expecting from the motor or the reading will roll over to 0, creating a control issue
#define USER_IQ_FULL_SCALE_CURRENT_A (20.0) // 20.0 Example for boostxldrv8301_revB typical usage

//! \brief Defines the maximum current at the AD converter
//! \brief The value that will be represented by the maximum ADC input (3.3V) and conversion (0FFFh)
//! \brief Hardware dependent, this should be based on the current sensing and scaling to the ADC input
#define USER_ADC_FULL_SCALE_CURRENT_A (33.0) // 33.0 boostxldrv8301_revB current scaling

//! \brief Defines the current scale factor for the system
//! \brief Compile time calculation for scale factor (ratio) used throughout the system
#define USER_CURRENT_SF ((float_t)((USER_ADC_FULL_SCALE_CURRENT_A)/(USER_IQ_FULL_SCALE_CURRENT_A)))

//! \brief Defines the number of current sensors used
//! \brief Defined by the hardware capability present
//! \brief May be (2) or (3)
#define USER_NUM_CURRENT_SENSORS (3) // 3 Preferred setting for best performance across full speed range, allows for 100% duty cycle

//! \brief Defines the number of voltage (phase) sensors
//! \brief Must be (3)
#define USER_NUM_VOLTAGE_SENSORS (3) // 3 Required

//! \brief ADC current offsets for A, B, and C phases
//! \brief One-time hardware dependent, though the calibration can be done at run-time as well
//! \brief After initial board calibration these values should be updated for your specific hardware so they are available after compile in the binary to be loaded to the controller
#define I_A_offset (0.844628096)
#define I_B_offset (0.838096201)
#define I_C_offset (0.847549021)

//! \brief ADC voltage offsets for A, B, and C phases
//! \brief One-time hardware dependent, though the calibration can be done at run-time as well
//! \brief After initial board calibration these values should be updated for your specific hardware so they are available after compile in the binary to be loaded to the controller
#define V_A_offset (0.267855585)
#define V_B_offset (0.267174721)
#define V_C_offset (0.266226828)

//! \brief CLOCKS & TIMERS
// **************************************************************************
//! \brief Defines the system clock frequency, MHz
#define USER_SYSTEM_FREQ_MHz (60.0)

//! \brief Defines the Pulse Width Modulation (PWM) frequency, kHz
//! \brief PWM frequency can be set directly here up to 30 KHz safely (60 KHz MAX in some cases)
//! \brief For higher PWM frequencies (60 KHz+ typical for low inductance, high current ripple motors) it is recommended to use the ePWM hardware
//! \brief and adjustable ADC SOC to decimate the ADC conversion done interrupt to the control system, or to use the software Que example.
//! \brief Otherwise you risk missing interrupts and disrupting the timing of the control state machine
#define USER_PWM_FREQ_kHz (15.0) //30.0 Example, 8.0 - 30.0 KHz typical; 45-80 KHz may be required for very low inductance, high speed motors

//! \brief Defines the maximum Voltage vector (Vs) magnitude allowed. This value sets the maximum magnitude for the output of the
//! \brief Id and Iq PI current controllers. The Id and Iq current controller outputs are Vd and Vq.
//! \brief The relationship between Vs, Vd, and Vq is: Vs = sqrt(Vd^2 + Vq^2). In this FOC controller, the
//! \brief Vd value is set equal to USER_MAX_VS_MAG*USER_VD_MAG_FACTOR. Vq = sqrt(USER_MAX_VS_MAG^2 - Vd^2).
//! \brief Set USER_MAX_VS_MAG = 0.5 for a pure sinewave with a peak at SQRT(3)/2 = 86.6% duty cycle. No current reconstruction is needed for this scenario.
//! \brief Set USER_MAX_VS_MAG = 1/SQRT(3) = 0.5774 for a pure sinewave with a peak at 100% duty cycle. Current reconstruction will be needed for this scenario (Lab10a-x).
//! \brief Set USER_MAX_VS_MAG = 2/3 = 0.6666 to create a trapezoidal voltage waveform. Current reconstruction will be needed for this scenario (Lab10a-x).
//! \brief For space vector over-modulation, see lab 10 for details on system requirements that will allow the SVM generator to go all the way to trapezoidal.
#define USER_MAX_VS_MAG_PU (2.0/3.0) // Set to 0.5 if a current reconstruction technique is not used. Look at the module svgen_current in lab10a-x for more info.

//! \brief Defines the address of estimator handle
//!
#define USER_EST_HANDLE_ADDRESS (0x600)

//! \brief Defines the direct voltage (Vd) scale factor
//!
#define USER_VD_SF (0.95)

//! \brief Defines the Pulse Width Modulation (PWM) period, usec
//! \brief Compile time calculation
#define USER_PWM_PERIOD_usec (1000.0/USER_PWM_FREQ_kHz)

//! \brief Defines the Interrupt Service Routine (ISR) frequency, Hz
//!
#define USER_ISR_FREQ_Hz ((float_t)USER_PWM_FREQ_kHz * 1000.0 / (float_t)USER_NUM_PWM_TICKS_PER_ISR_TICK)

//! \brief Defines the Interrupt Service Routine (ISR) period, usec
//!
#define USER_ISR_PERIOD_usec (USER_PWM_PERIOD_usec * (float_t)USER_NUM_PWM_TICKS_PER_ISR_TICK)

//! \brief DECIMATION
// **************************************************************************
//! \brief Defines the number of pwm clock ticks per isr clock tick
//! Note: Valid values are 1, 2 or 3 only
#define USER_NUM_PWM_TICKS_PER_ISR_TICK (3)

//! \brief Defines the number of isr ticks (hardware) per controller clock tick (software)
//! \brief Controller clock tick (CTRL) is the main clock used for all timing in the software
//! \brief Typically the PWM Frequency triggers (can be decimated by the ePWM hardware for less overhead) an ADC SOC
//! \brief ADC SOC triggers an ADC Conversion Done
//! \brief ADC Conversion Done triggers ISR
//! \brief This relates the hardware ISR rate to the software controller rate
//! \brief Typcially want to consider some form of decimation (ePWM hardware, CURRENT or EST) over 16KHz ISR to insure interrupt completes and leaves time for background tasks
#define USER_NUM_ISR_TICKS_PER_CTRL_TICK (2) // 2 Example, controller clock rate (CTRL) runs at PWM / 2; ex 30 KHz PWM, 15 KHz control

//! \brief Defines the number of controller clock ticks per current controller clock tick
//! \brief Relationship of controller clock rate to current controller (FOC) rate
#define USER_NUM_CTRL_TICKS_PER_CURRENT_TICK (1) // 1 Typical, Forward FOC current controller (Iq/Id/IPARK/SVPWM) runs at same rate as CTRL.

//! \brief Defines the number of controller clock ticks per estimator clock tick
//! \brief Relationship of controller clock rate to estimator (FAST) rate
//! \brief Depends on needed dynamic performance, FAST provides very good results as low as 1 KHz while more dynamic or high speed applications may require up to 15 KHz
#define USER_NUM_CTRL_TICKS_PER_EST_TICK (1) // 1 Typical, FAST estimator runs at same rate as CTRL;

//! \brief Defines the number of controller clock ticks per speed controller clock tick
//! \brief Relationship of controller clock rate to speed loop rate
#define USER_NUM_CTRL_TICKS_PER_SPEED_TICK (15) // 15 Typical to match PWM, ex: 15KHz PWM, controller, and current loop, 1KHz speed loop

//! \brief Defines the number of controller clock ticks per trajectory clock tick
//! \brief Relationship of controller clock rate to trajectory loop rate
//! \brief Typically the same as the speed rate
#define USER_NUM_CTRL_TICKS_PER_TRAJ_TICK (15) // 15 Typical to match PWM, ex: 10KHz controller & current loop, 1KHz speed loop, 1 KHz Trajectory

//! \brief Defines the controller frequency, Hz
//! \brief Compile time calculation
#define USER_CTRL_FREQ_Hz (uint_least32_t)(USER_ISR_FREQ_Hz/USER_NUM_ISR_TICKS_PER_CTRL_TICK)

//! \brief Defines the estimator frequency, Hz
//! \brief Compile time calculation
#define USER_EST_FREQ_Hz (uint_least32_t)(USER_CTRL_FREQ_Hz/USER_NUM_CTRL_TICKS_PER_EST_TICK)

//! \brief Defines the trajectory frequency, Hz
//! \brief Compile time calculation
#define USER_TRAJ_FREQ_Hz (uint_least32_t)(USER_CTRL_FREQ_Hz/USER_NUM_CTRL_TICKS_PER_TRAJ_TICK)

//! \brief Defines the controller execution period, usec
//! \brief Compile time calculation
#define USER_CTRL_PERIOD_usec (USER_ISR_PERIOD_usec * USER_NUM_ISR_TICKS_PER_CTRL_TICK)

//! \brief Defines the controller execution period, sec
//! \brief Compile time calculation
#define USER_CTRL_PERIOD_sec ((float_t)USER_CTRL_PERIOD_usec/(float_t)1000000.0)

//! \brief LIMITS
// **************************************************************************
//! \brief Defines the maximum negative current to be applied in Id reference
//! \brief Used in field weakening only, this is a safety setting (e.g. to protect against demagnetization)
//! \brief User must also be aware that overall current magnitude [sqrt(Id^2 + Iq^2)] should be kept below any machine design specifications
#define USER_MAX_NEGATIVE_ID_REF_CURRENT_A (-0.5 * USER_MOTOR_MAX_CURRENT) // -0.5 * USER_MOTOR_MAX_CURRENT Example, adjust to meet safety needs of your motor

//! \brief Defines the low speed limit for the flux integrator, pu
//! \brief This is the speed range (CW/CCW) at which the ForceAngle object is active, but only if Enabled
//! \brief Outside of this speed - or if Disabled - the ForcAngle will NEVER be active and the angle is provided by FAST only
#define USER_ZEROSPEEDLIMIT (0.5 / USER_IQ_FULL_SCALE_FREQ_Hz) // 0.002 pu, 1-5 Hz typical; Hz = USER_ZEROSPEEDLIMIT * USER_IQ_FULL_SCALE_FREQ_Hz

//! \brief Defines the force angle frequency, Hz
//! \brief Frequency of stator vector rotation used by the ForceAngle object
//! \brief Can be positive or negative
#define USER_FORCE_ANGLE_FREQ_Hz (2.0 * USER_ZEROSPEEDLIMIT * USER_IQ_FULL_SCALE_FREQ_Hz) // 1.0 Typical force angle start-up speed

//! \brief Defines the maximum current slope for Id trajectory during PowerWarp
//! \brief For Induction motors only, controls how fast Id input can change under PowerWarp control
#define USER_MAX_CURRENT_SLOPE_POWERWARP (0.3*USER_MOTOR_RES_EST_CURRENT/USER_IQ_FULL_SCALE_CURRENT_A/USER_TRAJ_FREQ_Hz) // 0.3*RES_EST_CURRENT / IQ_FULL_SCALE_CURRENT / TRAJ_FREQ Typical to produce 1-sec rampup/down

//! \brief Defines the starting maximum acceleration AND deceleration for the speed profiles, Hz/s
//! \brief Updated in run-time through user functions
//! \brief Inverter, motor, inertia, and load will limit actual acceleration capability
#define USER_MAX_ACCEL_Hzps (20.0) // 20.0 Default

//! \brief Defines maximum acceleration for the estimation speed profiles, Hz/s
//! \brief Only used during Motor ID (commission)
#define USER_MAX_ACCEL_EST_Hzps (5.0) // 5.0 Default, don't change

//! \brief Defines the maximum current slope for Id trajectory during estimation
#define USER_MAX_CURRENT_SLOPE (USER_MOTOR_RES_EST_CURRENT/USER_IQ_FULL_SCALE_CURRENT_A/USER_TRAJ_FREQ_Hz) // USER_MOTOR_RES_EST_CURRENT/USER_IQ_FULL_SCALE_CURRENT_A/USER_TRAJ_FREQ_Hz Default, don't change

//! \brief Defines the fraction of IdRated to use during rated flux estimation
//!
#define USER_IDRATED_FRACTION_FOR_RATED_FLUX (1.0) // 1.0 Default, don't change

//! \brief Defines the fraction of IdRated to use during inductance estimation
//!
#define USER_IDRATED_FRACTION_FOR_L_IDENT (1.0) // 1.0 Default, don't change

//! \brief Defines the IdRated delta to use during estimation
//!
#define USER_IDRATED_DELTA (0.00002)

//! \brief Defines the fraction of SpeedMax to use during inductance estimation
//!
#define USER_SPEEDMAX_FRACTION_FOR_L_IDENT (1.0) // 1.0 Default, don't change

//! \brief Defines flux fraction to use during inductance identification
//!
#define USER_FLUX_FRACTION (1.0) // 1.0 Default, don't change

//! \brief Defines the PowerWarp gain for computing Id reference
//! \brief Induction motors only
#define USER_POWERWARP_GAIN (1.0) // 1.0 Default, don't change

//! \brief Defines the R/L estimation frequency, Hz
//! \brief User higher values for low inductance motors and lower values for higher inductance
//! \brief motors. The values can range from 100 to 300 Hz.
#define USER_R_OVER_L_EST_FREQ_Hz (300) // 300 Default

//! \brief POLES
// **************************************************************************
//! \brief Defines the analog voltage filter pole location, Hz
//! \brief Must match the hardware filter for Vph
#define USER_VOLTAGE_FILTER_POLE_Hz (364.682) // 364.682, value for boostxldrv8301_revB hardware

//! \brief Defines the analog voltage filter pole location, rad/s
//! \brief Compile time calculation from Hz to rad/s
#define USER_VOLTAGE_FILTER_POLE_rps (2.0 * MATH_PI * USER_VOLTAGE_FILTER_POLE_Hz)

//! \brief Defines the software pole location for the voltage and current offset estimation, rad/s
//! \brief Should not be changed from default of (20.0)
#define USER_OFFSET_POLE_rps (20.0) // 20.0 Default, do not change

//! \brief Defines the software pole location for the flux estimation, rad/s
//! \brief Should not be changed from default of (100.0)
#define USER_FLUX_POLE_rps (100.0) // 100.0 Default, do not change

//! \brief Defines the software pole location for the direction filter, rad/s
#define USER_DIRECTION_POLE_rps (6.0) // 6.0 Default, do not change

//! \brief Defines the software pole location for the speed control filter, rad/s
#define USER_SPEED_POLE_rps (100.0) // 100.0 Default, do not change

//! \brief Defines the software pole location for the DC bus filter, rad/s
#define USER_DCBUS_POLE_rps (100.0) // 100.0 Default, do not change

//! \brief Defines the convergence factor for the estimator
//! \brief Do not change from default for FAST
#define USER_EST_KAPPAQ (1.5) // 1.5 Default, do not change

---------------------

Cheers,

Rich

continuing using the LAUNCH + BOOST for this motor, not the DRV8301 EVM.

your PWM and timing is completely wrong, that's the problem.
you are using a PWM of 15 KHz, then dividing by 3 for a 5 KHz interrupt rate.
you are then dividing that by 2 for a 2.5 KHz CTRL and EST rate.

please use the default values of
#define USER_PWM_FREQ_kHz (45.0)
#define USER_NUM_PWM_TICKS_PER_ISR_TICK (3)
#define USER_NUM_ISR_TICKS_PER_CTRL_TICK (1)

for an effective 15 KHz Interrupt/CTRL/EST rate.


#elif (USER_MOTOR == Maxon)
#define USER_MOTOR_TYPE MOTOR_Type_Pm
#define USER_MOTOR_NUM_POLE_PAIRS (7)
#define USER_MOTOR_Rr (NULL)
#define USER_MOTOR_Rs (NULL)
#define USER_MOTOR_Ls_d (NULL)
#define USER_MOTOR_Ls_q (NULL)
#define USER_MOTOR_RATED_FLUX (NULL)
#define USER_MOTOR_MAGNETIZING_CURRENT (NULL)
#define USER_MOTOR_RES_EST_CURRENT (2.0)
#define USER_MOTOR_IND_EST_CURRENT (-2.0)
#define USER_MOTOR_MAX_CURRENT (10.0)
#define USER_MOTOR_FLUX_EST_FREQ_Hz (40.0)


try proj_lab02c again for motor ID.

then you can use proj_lab05a for torque control or proj_lab10a for speed control with over-modulation.

Hello,

Well I should point out that I've ramped up the PWM freq to 60kHz before now...

Anyway, I tried your suggestions and performance isn't an improvement, far from it in fact. The motor stalls very quickly at let than 1Hz and the result of the parameter estimation isn't much better but is at least nearer to the spec sheet than a run at less than 20kHz (but still 20% away).

The version of Motorware I used last year (maybe ..10) seemed to work just fine. Same motor, no problems.

Suggestions are welcome,

Rich

this motor has a very small flux, I would not expect it to run at < 1 Hz at all, regardless of version of MotorWare

a motor like this is more suited for something like ~10-20 Hz loaded operation.

which parameters are different than your spec sheet? Why do you trust that sheet more than the ID of your actual motor? have you tried measuring line-line with an LCR meter?

Hello,

No need to pay attention to the spec sheets, let alone trust what they say. I have previously tried three 270 micro Henry inductors in WYE formation instead of the motor to measure if the unit is damaged or not. It read within 5% of the measured (with LCR) value, well at least in that test.

What intrigues me is why the motor doesn't turn. The 28027 code should spool-up the motor to reasonable speed while measuring the parameters but unfortunately it gets to less that one revolution per second and then stalls. Clearly the field is rotating as the motor is vibrating.

I don't want this to be the motor that the boards couldn't spin as I'm in a hurry to get a working system together and really need help with this.

Cheers,

Rich  

Rich,
I suspect it's something simple. If you want to send me the motor I'm happy to get it running on my side.

Hello Chris,

A faster route is for a WebEx session and I can show you what's happening with the motor, what the effects are, what the (simple) changes need to be can be implemented quickly.

How does that sound?

Rich